Variable centroid projectile



Dec. 23, 1969 H. G. MORGAN 3,435,173

VARIABLE CENTROID PROJECTILE Filed Feb. 6, 1968 INVENTOR. HARVEY G. MORGAN United States Patent ()fiice 3,485,173 Patented Dec. 23, 1969 US. Cl. 10292.2 4 Claims ABSTRACT OF THE DISCLOSURE A projectile having a variable center of mass comprised of the projectile having a hollow portion containing a ball bearing therein which shifts according to the action of the projectile to increase by at least 30% the kinetic energy left in the target.

The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without the payment to me of any royalty thereon.

The invention relates to a projectile and more particularly to a variable centroid projectile including a ball bearing freely movable in a hollow portion of the projectile to provide a variable center of mass.

The problem of increasing the energy remaining in the target has been acute for many years. In the past, when a projectile struck a soft medium target, it continued to travel therethrough in the same flight path because there was no means to cause deviation thereof. It is well known in the field of ballistics that spinned stabilized projectiles leave only -15% of their available energy in soft targets because they do not tumble in it, but pass straight through. Spinned stabilized projectiles do not tumble because their spin rate is so high that they are stable not only in air, but also in a more dense media.

Some of the previous methods tried were the use of soft or lead nosed projectiles which deformed upon impact; the use of hollow point projectiles which blow apart on impact, and under spinning the projectile which is accomplished by not giving the projectile the proper twist in the barrel. The lead nose and hollow point projectiles were satisfactory if the target media was dense enough to cause deformation and the under spinning method was unsatisfactory because at 65 F. they became unstable at projectile exit.

The present invention solves the aforementioned conditions by leaving at least 3040% of its energy in the target, thus causing an increase in effectiveness. A projectile since it has mass and a certain velocity when it strikes a target does so with a definite kinetic energy level. Consequently, when said projectile passes through a denser medium it loses velocity and imparts a certain amount of its kinetic energy to the target in the form of heat. When a projectile constructed as taught herein, strikes a target with 2,000 ft./lbs. of energy, it exits the target with only 1,4001,200 ft./lbs. of energy. The 600- 800 ft./lbs. of energy is imparted to the target to do damage. The conventional spin stabilized projectile only imparts between 200-300 ft./lbs. of energy to the target and consequently does far less damage thereto.

It is therefore an object of the present invention to provide a projectile capable of leaving from 30-40% of its available energy in the target.

Another object is the provision of a projectile which has increased effectiveness in a soft-medium target.

A further object is to provide a projectile which Will tumble in a soft-medium target.

The above objects as well as others together with the benefits and advantages of the invention Will be apparent upon reference to the detailed description set forth below, particularly when taken in conjunction with the drawing annexed hereto in which a projectile is indicated generally by reference character 10. Said projectile 10 includes a hollow cavity 12 in its base portion 14. Said cavity 12 is sealed by a primer cup 16 and has contained therein a metallic ball bearing 18. Said ball 18 is of slightly less diameter than the inner diameter of cavity 12 and is therefore free to roll around. The ball bearing 18 can be constructed of steel, tungsten, lead or the like and can be round, cylindrical or of any other similar shape. Upon firing, the ball bearing is pushed backward against the seal 16 by inertia and upon impact, due to the projectiles sudden loss of velocity, is forced forward toward the nose 20 of the projectile 10. This action results in the projectiles center of gravity shifting which causes a tumbling action of the projectile.

A specific embodiment of the present invention would be in the M- projectile, in which a cavity .500 inch deep and .152 inch wide is drilled. The primer cup utilized to seal the cavity would be of caliber .22. The projectile is then loaded into a conventional 7.62 mm. case and fired from conventional weapons such as the M-14 rifle or the M-60 and M73 machine guns. The projectile weighs about grains which is about 12.0 grains less than the conventional M-8O projectile if a steel ball bearing is used, or it can be made to weigh 147 grains, which is the same as the conventional M80, if a tungsten alloy ball is used.

I claim:

1. A projectile comprising a partially hollow body,

a nose portion forward of said hollow body,

a base portion rearward of said nose portion and providing the opening to said hollow body portion, seal means in said base portion to close otf said hollow portion, and

means contained within said hollow portion to cause tumbling of the projectile upon impact in a softmedium target.

2. A projectile of the type described in claim 1 wherein said means contained within said hollow portion is a ball bearing.

3. A projectile of the type described in claim 2 wherein said ball bearing is metallic.

4. A projectile of the type described in claim 3 wherein said metallic ball bearing is constructed of a material selected from the group consisting of steel, lead and tungsten.

References Cited UNITED STATES PATENTS 911,591 2/1909 Hoxie 10291 X 3,282,214 11/1966 Briscoe 102-38 3,088,407 5/ 1963 Gallagher et al. 244-31 3,442,205 5/1969 Stadler et a1. 10292.7

FOREIGN PATENTS 297,683 1932 Italy.

22,394 7/1921 France.

BENJAMIN A. BORCHELT, Primary Examiner JAMES FOX, Assistant Examiner US. Cl. X.R. 10238; 244-3.1 

